Objective: To investigate the relationship between aquaporin-4(AQP4) expression and brain water content in brain edema after cerebral ischemic/reperfussion(I/R) in rats. Method: Total 50 adult male Sprague-Dawley rats were randomly divided into sham group and 6

12

24

48 h cerebral ischemic/reperfussion groups. Brain water content was measured by the Wet-dry method and the expression of AQP4 was observed by Western blot. Result: Brain water content and APQ4 expression of ischemic side in model group was increased with delayed I/R period

and at 24 h the change was most marked

brain water content increased significantly and AQP4 expression increased from 12 h to 24 h

There was a slight decrease at 48 h. The difference of brain water content and APQ4 expression in contralateral side was not significant among different time points. The data were analyzed by method of Spearman

the results showed that the correlation was significant(P<0.05). Conclusion: The consistency is obvious between the change of AQP4 expression and brain edema in ischemic side after cerebral ischemic reperfusion.